smtp ==== Email with attachment --------------------- :: Content-Type: multipart/mixed; boundary=${separator}; charset="utf8" From: first.last@sub.domain.tld To: first.last@sub.domain.tld Subject: Email subject --${separator} Content-Type: text/plain; charset="utf8" Email body --${separator} Content-Disposition: attachment; filename="file name" Content-Transfer-Encoding: base64 Content-Type: application/octet-stream … --${separator}--